When is the right time to stop feeding hay?
Spring has sprung and so has the green forages in pastures.
“The animals are ready to be eating green grass this time of year and they usually chase green grass this time of year,” Sarah Kenyon, Ph.D., University of Missouri Field Specialist in Agronomy, said. “Everyone is ready. Farmers and animals alike are ready for livestock to get on that green forage.”
As exciting as it is to see green grass in the fields, agronomists urge patience and careful consideration before turning livestock out on the new grass. Letting cattle graze on pastures too soon can cause damage and deter plant growth in the long run.
Once it starts to grow, agronomists advise giving the grass time to develop a hardy root system. “During grazing, the roots have to recover as well as the top growth,” Kenyon explained. “Waiting can help the roots recover and creates healthy productive pastures.”
In the spring, grass needs to put down deep roots and develop hardy root reserves in order for it to grow well throughout the season. “It will really not start growing voraciously until it rebuilds those root reserves,” Nathan Bilke, District Conservationist with USDA’s Natural Resources Conservation Service, said.
When producers should stop feeding hay and when they should open up newly green fields to their livestock, depends largely on how the land was managed the year before. If it was heavily grazed or carried a high stock density late into fall, the pastures require more time to recover.
Thinking about the science behind plant growth can help producers decide when to start allowing their livestock to graze a field. “It’s all about understanding the way grass grows,” Bilke explained. “Grass has to have blades, or solar panels if you will, for it to grow. When we switch those off by grazing too hard, overstocking or whatever, then we set that plant back and cause it to come out of dormancy later in the spring.”
Experts suggest a general rule of thumb is to hold off livestock until the grass reaches 6 to 12 inches. As hard as it may be to wait, patience should pay off. “Waiting until it has accumulated a certain level of growth can help those pastures recover from the winter stress and the previous freezing event,” Kenyon said. “During grazing, the roots have to recover as well as the top growth.”
Once the livestock is on the pasture, keeping a three-inch blade height will help the grass grow faster and remain healthy, this is especially important for tall fescue and orchard grass. “Leaving the three-inch stubble height behind maintains the growing points and keeps green tissue present so it can photosynthesize after grazing,” Kenyon explained.
In tall fescue pastures, rotating cattle before they graze the grass below three inches, also prevents cattle from eating down to the bottom two inches, where a majority of the fescue toxins are concentrated.
One option for producers eager to get their animals on green grass is a hybrid grazing approach. “One thing to consider is put them on grass for part of the day and then move them to a hay yard for the remainder of the day and the overnight – to kind of help satisfy both things,” Kenyon suggested. This allows producers to rest the pastures and accumulate forage while easing into the grazing season at the same time.
